Loading issues with Cubase 5

Hi there

The issue I am having is with trying to open cubase 5 project created on windows 10 and it not loading on windows 7.

The problem I am having is that I record the tracks on Cubase5 and then take those to my friends studio - he is also using Cubase 5 - but my computer is Windows 10 while his is Windows 7 and when he tries to load my project onto his computer, the program locks up.

Has this happened to anyone else on the forum. Would appreciate any feedback on this as it has us stumped.